Last post on Nov 27, 2011 at 12:06 PM
You are in the Toyota Sienna
What is this discussion about?
Toyota Sienna, Heating / Cooling, Van
#1 of 16 2007 Sienna A/C Problem
May 31, 2011 (12:33 pm)
I have a 2007 Sienna with the following problem. The A/C coming out of the front left two vents is warm while the two vents towards the right seem to be emitting correct cool air.
First of all, what is probably the issue?
Second of all, I have an extended Toyota warranty. Will this problem be covered under it?
#2 of 16 Re: 2007 Sienna A/C Problem [hanistor]
Jun 01, 2011 (9:16 am)
Not sure what the cause is but I do expect a bumper-to-bumper extended warranty would cover the HVAC system.
#3 of 16 Re: 2007 Sienna A/C Problem [hanistor]
Jun 02, 2011 (5:10 am)
You didn't tell us whether this was a manual system (CE/LE) with single front control, or an automatic (XLE/Limited) with split front temp control, so helping you is very difficult.
It could be a dash control issue, or a problem with the damper server control motor (or air door) on the blower assembly buried deep under the dash.
Still under warranty? Check the warranty paperwork for these terms to see if you are covered.
#4 of 16 Re: 2007 Sienna A/C Problem [fibber2]
Jun 02, 2011 (9:51 am)
It's a manual system (CE/LE) with single front control. It's very puzzling because in the middle of the dash there are two vents right next to each other. The one on the right (along with the vent next to the passenger window) blows cold while one on the left (along with the vent next to the drivers window blows cold.
I have an extended warranty and took it to the dealer yesterday. They wanted to evacuate and recharge the system for $189 and put in a dye "then if you really have a problem, we'll be able to pinpoint the problem". I told them forget about it!
Any educated guesses?
#5 of 16 Re: 2007 Sienna A/C Problem [hanistor]
Jun 02, 2011 (1:17 pm)
Base unit. Interesting… I was betting on it being the split system based on your left/right temp disparity.
If it is blowing cold from some of the front vents, and if it blows cold from the rear system, then a evacuation & recharge sounds unnecessary. But as you walked, I’m willing to bet that you already knew that! Go to an autoparts place and pick up a $5 AC thermometer and record the actual air temp differences. Make sure the vehicle is in the shade, and run long enough that any hot dash pad issues don't factor in.
Warranty – Gold or Platinum? Looking at what’s covered with either plan, I see a collection of parts, but no mention about performance. If all lines and tubes, the compressor, evaporator, condenser, receiver/dryer, fill valves, seals and gaskets are covered, I’d then assume that it’s considered to be closed & sealed, so no leakage should occur. Therefore, I’d say that any recharge service needed because of a part failure should be on them. But I’ll bet that they don’t see it that way. They’d probably replace a leaking fitting, but stick you with the bill for sucking it down and recharging. Caught in a technicality….
Now lets assume that your split performance is due to a damper door motor issue. Unfortunately, the damper servo is only covered by the Platinum plan. So you might be out yet again.
Unfortunately, I don’t have the troubleshooting section of the shop manual, so I cannot see details of the operation & airflow, just a listing of parts. Let me see if I can find something else out on the web.
#6 of 16 Re: 2007 Sienna A/C Problem [fibber2]
Jun 02, 2011 (1:31 pm)
Thanks for taking the time to reply. I truly appreciate it.
Of course, as you probably realized, i meant to say "while one on the left (along with the vent next to the drivers window) blows warm".
By the way, I have a 8 year 100,000 miles Toyota Platinum Zero Deductible Warranty. Car has 52K miles.
#7 of 16 Re: 2007 Sienna A/C Problem [hanistor]
Jun 03, 2011 (5:17 am)
You are most welcome! Still looking for details on the normal operation.
As you probably already realize, if you look down the center with a flashlight, the vents are indeed totally separate branches. It makes sense to me that the halves could run at different temps if a door is stuck, as that's by design what the upgraded system is supposed to provide.
In the old days, a manual control system ran with levers and cables. On this vehicle, the 'manual' controls are connected to a circuit board, and all operation is totally electronic. It shares a lot of elements with the fully automatic, dual control system.
I'll keep looking, but ultimately you will have to battle it out with the dealership. Present them with temperature output values to support your case. You might have to find another dealership if yours won't cooperate.
#8 of 16 Re: 2007 Sienna A/C Problem [fibber2]
Jun 03, 2011 (2:33 pm)
OK, I think I’m ready to make my prediction. It’s based on scant evidence, but here goes! If I get this right, you owe me a virtual beer. Maybe two….
The manual models and the automatic dual zone models use a very similar, but not identical mixing box called out in the exploded diagram as a “Radiator Assembly, Air Conditioner”. There is no interior detail offered. Only the things that plumb into it from the outside are individually identified.
Part number for the CE/LE is **050-08050, list price is $1,250
Part number for the XLE/Limited is **050-08060, list price is $1,500
It is basically a mixing box with the following: evaporator core of the AC on one side, the heater core on the other, and a variable baffle between them. Plus the inlet from the fan unit, and output doors to the defroster, floor vents (left & right), and the dash vents (left & center-left, and center-right & right).
Here’s where it gets interesting. The CE/LE has one exterior mounted “Servo Subassembly Damper for Air Mix” mounted on the fan (passengers) side. The LE has this same one, plus a matching damper on the drivers side. Otherwise, the drawings and almost all of the other part numbers are identical.
Here’s my theory: On the dual climate system, the damper is split and each side is run independently (left & right servos). On the manual system, that one servo runs a double length damper, or two dampers connected by a linkage. In your case, something in this connection between left & right damper is stuck or broken, and only the directly connected half is responding properly.
And structurally that would make sense - you said that the right side seemed to work right, the left side isn't.
Do you have kids? Any chance someone dropped a pencil down the left-center vent? I hate to see you eat a $2k parts & labor bill if you could pull something out of there!
#9 of 16 Re: 2007 Sienna A/C Problem [hanistor]
Jun 20, 2011 (12:17 pm)
My 2007 Sienna LE has exact same AC problem with yours. The driver side AC is much warmer than the passenger side. I just discovered this issue 2 months ago (because of the hot summer in Texas). So far after I drive for 20 minutes, the driver side AC will get colder most of the time (but not always). I am afraid it will get as worse as yours in the near future. Let me know if you find the DIY solution instead of sepnding 2K from the dealers.
#10 of 16 Re: 2007 Sienna A/C Problem [fibber2]
Jun 20, 2011 (1:10 pm)
Sorry for not responding earlier, Fibber2. I did not see your post till today...
To answer your question, yes, I do have kids. 7 of them. That's why I'm driving a Sienna and not a Sonata, for example. I'm looking forward to the day when I can buy a regular car, once again.
Thanks for the detailed hypothesis. You may ultimately be correct but, in the meantime, I drove my car to a friends repair garage 60 miles away. His guy thought it would be a good idea to top off the system. Ultimately, (it was a cool day) they did evacuate the system and refill it (~$120) and it has worked well for the 8 days since. I'll keep you posted but will gladly buy you a beer if we ever meet up, either way.